Traditionally, blood is regarded as among the most difficult kinds of stain, along with ink and grease, to clean and remove. Removing blood stains, for example, from clothing is an arduous and timely process where care has to be used so as not to set the stain into the fabric permanently. The typical process involves rinsing the fabric with cold salt water (not hot water as this would set the stain into the fabric making it almost impossible to remove). Next, the fabric is soaked in cold water containing an enzyme-based detergent or meat tenderizer for about 30-60 minutes. One would then apply a laundry pre-soak and then launder with enzyme-based detergent. (See e.g., FIELD GUIDE TO STAINS, pp. 199-202, Quirk Publications, Inc. ©2002) This course of treatment can be truly a time consuming process.
Recent stain removers use an oxidant method for removing blood stains, for example, applying an oxidizing agent to the stain-affected area. U.S. Pat. No. 6,730,819 claims the use of oxidizing agents, including oxides, peroxides, ozonides, and superoxides. Most of these agents are irritants or caustic to human skin and therefore not suitable for use in various consumer products, such as feminine hygiene pads or other applications that contact skin. In a series of studies, Consumer Reports, a leading U.S. publication for consumer products, evaluated currently available commercial spot and stain-removers and found that they either do not work effectively against or are not recommended for blood, ink or grease spots or stains. (See, CONSUMER REPORTS, “Seeing Spots? Don't Rely on Quick Stain Removers,” p. 9, August 2006; CONSUMER REPORTS, “Stain Removers. Which are Best,” p. 52, March 2000; and CONSUMER REPORTS “On-the-Spot Cleanup,” p. 10, June 1998.) Some of the commercial spot and stain removers state explicitly on their packaging “not effective on blood, ink and grease.”
Currently, given the absence of a viable composition or commercial product, a need exists for a better kind of stain remover, especially one that works well on blood, ink, or grease, among other colorants or stains. Workers in various different industries, such as relating to household or industrial cleaning, laundry, textiles, cosmetics, or health and hygiene, will appreciate a stringent, but less caustic stain removing formulation that can neutralize or discharge various kinds of colorants at a relatively rapid rate. The formulation should be inexpensively derived from natural products and may be applied to articles that can contact naked skin or on a variety of different materials and in a variety of products without harmful effects.